|Released|Title|Artist|Format|Language|
|---|---|---|---|---|
|20 January 2011|V.V.I.P|Seungri|Mini Album, Digital Download|Korean|
|24 February 2011|Tonight|Big Bang|Mini Album, Digital Download|Korean|
|8 April 2011|BIGBANG Special Edition|Big Bang|Studio Album, Digital Download|Korean|
|11 May 2011|Big Bang 2|Big Bang|Studio Album, Digital Download|Japanese|
|25 May 2011|The Ultimate: International Best|Big Bang|Compilation|Japanese|
|30 June 2011|2011 Big Show Live Concert|Big Bang|Live Album|Korean|
|28 July 2011|2NE1|2NE1|Extended play, Digital Download|Korean|
|21 September 2011|Nolza|2NE1|Extended play, Digital Download|Japanese|
|21 October 2011|Fever's End: Part 1|Tablo|Studio Album, Digital Download|Korean|
|1 November 2011|Fever's End: Part 2|Tablo|Studio Album, Digital Download|Korean|
|21 December 2011|1st Live Concert Nolza!|2NE1|Live Album|Korean|
|29 April 2011|Loveless|Gummy|Mini Album, Digital Download|Japanese|
|14 December 2011|The Best of BIGBANG|Big Bang|Compilation|Japanese|

Question: how many "compilation" albums did yg entertainment release in 2011?
Answer: 2